Composite materials containing nanoparticles and their use in chromatography

Abstract

Novel porous materials comprising nanoparticles, use in chromatographic separations, processes for its preparation, and separations devices containing the chromatographic material are described by the instant invention. In particular, the disclosure describes porous inorganic/organic hybrid particles embedded with nanoparticles selected from oxides or nitrides of the following: silicon carbide, aluminum, diamond, cerium, carbon black, carbon nanotubes, zirconium, barium, cerium, cobalt, copper, europium, gadolinium, iron, nickel, samarium, silicon, silver, titanium, zinc, boron, and mixtures thereof.

What is claimed is: 
     
       1. A method of preparing a composite material comprising dispersing one or more types of nanoparticles within a polyoligomeric organosiloxane to form a dispersion mixture, and condensing the dispersion mixture hydrolytically, such that a composite material is prepared, the composite material comprising a nanoparticle dispersed within an inorganic or hybrid material derived from one or more components selected from the group consisting of an organic repeat unit; an organosilyl repeat unit; and an inorganic repeat unit, wherein the composite material is represented by the following formula
   Np/(A) w (B) x (C) y    
 wherein:
 w, x, and y are each independently a positive number ranging from 0 to 1, such that w+x+y=1; 
 Np represents the nanoparticle, the nanoparticle comprising one or more moieties selected from silicon carbide, diamond, cerium, carbon black, carbon nanotubes, aluminum, zirconium, barium, cobalt, copper, europium, gadolinium, iron, nickel, samarium, silver, titanium, zinc, boron, oxides thereof, and nitrides thereof; 
 A represents the organic repeat unit; 
 B represents the organosilyl repeat unit; 
 C represents the inorganic repeat unit; and 
 
 wherein each repeat unit is covalently bonded to one or more separate repeat units A, B, or C. 
 
     
     
       2. The method of  claim 1 , wherein the polyoligomeric organosiloxanes is formed from the partial condensation of one or more components selected from the group consisting of an organic repeat unit; an organosilyl repeat unit; an inorganic repeat unit; and any combination thereof. 
     
     
       3. The method of  claim 1 , wherein the components are selected from the group consisting of organofunctional silane, a tetraalkoxysilane, a mixture of two or more organofunctional silanes, and a mixture of one or more organofunctional silanes with a tetraalkoxysilane. 
     
     
       4. The method of  claim 3 , wherein the tetraalkoxysilane is tetraethoxysilane or tetramethoxysilane. 
     
     
       5. The method of  claim 1 , wherein the organic repeat unit is incorporated into the composite material by reaction of an organic olefin repeat unit selected from the group consisting of divinylbenzene, styrene, vinylbenzylchloride, ethylene glycol dimethacrylate, 1-vinyl-2-pyrrolidinone, N-vinylcaprolactam, tert-butylmethacrylate, acrylamide, methacrylamide, N,N′-(1,2-dihydroxyethylene)bisacrylamide, N,N′-ethylenebisacrylamide, N,N′-methylenebisacrylamide, butyl acrylate, ethyl acrylate, methyl acrylate, 2-(acryloxy)-2-hydroxypropyl methacrylate, 3-(acryloxy)-2-hydroxypropyl methacrylate, trimethylolpropane triacrylate, trimethylolpropane ethoxylate triacrylate, tris[(2-acryloyloxy)ethyl] isocyanurate, acrylonitrile, methacrylonitrile, itaconic acid, methacrylic acid, trimethylsilylmethacrylate, N-[tris(hydroxymethyl) methyl]acrylamide, (3-acrylamidopropyl)trimethylammonium chloride, [3-(methacryloylamino)propyl]dimethyl(3-sulfopropyl)ammonium hydroxide inner salt, 
       
         
           
           
               
               
           
         
       
     
     
       6. The method of  claim 1 , wherein the organosilyl repeat unit is incorporated into the composite material by reaction of a functionalized silane selected from the group consisting of methacryloxypropyl trimethoxysilane, methacryloxypropyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, N-(3-acryloxy-2-hydroxypropyl)-3-aminopropyl triethoxysilane, (3-acryloxypropyl) trimethoxysilane, O-(methacryloxyethyl)-N-(triethoxysilylpropyl)urethane, N-(3-methacryloxy-2-hydroxypropyl)-3-aminopropyl triethoxysilane, methacryloxy methyltriethoxysilane, methacryloxymethyl trimethoxysilane, methacryloxypropy methyldiethoxysilane, methacryloxypropylmethyldimethoxysilane, methacryl oxypropyltris (methoxyethoxy)silane, 3-(N-styrylmethyl-2-aminoethylamino) propyltrimethoxysilane hydrochloride, 
       
         
           
           
               
               
           
         
       
       wherein
 each R is independently H or a C 1 -C 10  alkyl group and wherein R′ is independently H or a C 1 -C 10  alkyl group. 
 
     
     
       7. The method of  claim 1 , wherein the organosilyl repeat unit is incorporated into the composite material by reaction of a functionalized silane selected from the group consisting 
       
         
           
           
               
               
           
         
         wherein R is C 1 -C 18  alkoxy, C 1 -C 18  alkyl, or C 1 -C 18  alkyl; R 1  is C 1 -C 18  alkoxy, C 1 -C 18  alkyl, or C 1 -C 18  alkyl; R 2  is C 1 -C 18  alkyl, C 2 -C 18  alkenyl, C 2 -C 18  alkynyl, C 3 -C 18  cycloalkyl, C 1 -C 18  heterocycloalkyl, C 5 -C 18  aryl, or C 1 -C 18  heteroaryl; X is C 1 -C 18  alkoxy or C 1 -C 18  alkyl; and n is 1-8. 
       
     
     
       8. The method of  claim 1 , wherein the organosilyl repeat unit is incorporated into the composite material by reaction of a functionalized silane selected from the group consisting of bis(triethoxysilyl)ethane; bis(triethoxylsilyl)octane; bis(methyldiethoxysilyl)ethane; bis(triethoxysilyl)ethene; bis(trimethoxysilylethyl)benzene; ethyltriethoxysilane; diethyldiethoxysilane; mercaptopropyltriethoxysilane; methyltriethoxysilane; vinyltriethoxysilane; hexyltriethoxysilane; chloropropyltriethoxysilane; phenylethyltrimethoxysilane; octadecyltrimethoxysilane; octyltrimethoxysilane; 3,3.3-trifluoropropyltrimethoxysilane; 3-cyanobutyltriethoxysilane; phenyltriethoxysilane; acetyloxyethyltrimethoxysilane; chloroethyltriethoxysilane; and fluorotriethoxysilane. 
     
     
       9. The method of  claim 1 , wherein the organosilyl repeat unit is incorporated into the composite material by reaction of a functionalized silane: (bis(triethoxysilyl)ethane) 
       
         
           
           
               
               
           
         
       
     
     
       10. The method of  claim 1 , wherein the inorganic repeat unit is incorporated into the composite material by reaction of an alkoxysilane selected from the group consisting of tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane. 
     
     
       11. The method of  claim 1 , wherein the tetraalkoxysilane is tetramethoxysilane or tetraethoxysilane. 
     
     
       12. The method of  claim 1 , wherein the hydrolytic condensation is acid- or base-catalyzed. 
     
     
       13. The method of  claim 1 , wherein the condensation is performed in a solvent selected from the group consisting of water, methanol, ethanol, propanol, isopropanol, butanol, tert-butanol, pentanol, hexanol, cyclohexanol, hexafluoroisopropanol, cyclohexane, petroleum ethers, diethyl ether, dialkyl ethers, tetrahydrofuran, acetonitrile, ethyl acetate, pentane, hexane, heptane, benzene, toluene, xylene, N,N-dimethylformamide, dimethyl sulfoxide, 1-methyl-2-pyrrolidinone, methylene chloride, chloroform, and combinations thereof. 
     
     
       14. The method of  claim 1 , wherein the composite material is in the form of particles having an average diameter of 0.1 to 300 μm. 
     
     
       15. The method of  claim 1 , wherein a pore structure of the composite material is modified by further including a surfactant or combination of different surfactants, and by subjecting said material to hydrothermal treatment. 
     
     
       16. The method of  claim 1 , further comprising the step of surface modifying the composite material. 
     
     
       17. The method of  claim 16 , wherein the composite material has been surface modified by a surface modifier selected from the group consisting of an organic group surface modifier, a silanol group surface modifier, a polymeric coating surface modifier, and combinations thereof. 
     
     
       18. The method of  claim 16 , wherein the composite material has been surface modified with a surface modifier having the formula Z a (R′) b Si—R, where Z═Cl, Br, I, C 1 -C 5  alkoxy, dialkylamino or trifluoromethanesulfonate; a and b are each an integer from 0 to 3 provided that a+b=3; R′ is a C 1 -C 6  straight, cyclic or branched alkyl group, and R is a functionalizing group. 
     
     
       19. The method of  claim 17 , wherein the composite material has been surface modified by coating with a polymer. 
     
     
       20. The method of  claim 17 , wherein the composite material has been surface modified by silanol group modification. 
     
     
       21. The method of  claim 1 , wherein the nanoparticle is selected from diamond, zirconium oxide (amorphous, monoclinic, tetragonal and cubic forms), titanium oxide (amorphous, anatase, brookite and rutile forms), aluminum (amorphous, alpha, and gamma forms), and boronitride (cubic form). 
     
     
       22. The method of  claim 1 , wherein the nanoparticle is selected from diamond and silicon carbide.